Mk II Weapons

Updated: 3 minutes to read

Mk II weapons are upgraded variants of weapons sold from Ammu-Nation that offer better performance and more diverse accessories. This page covers Mk II upgrades of weapons recommended in the previous pages that bring significant improvements over their original counterpart.


To upgrade qualified weapons to their Mk II variant, you must own a Weapon Workshop. You can get a Weapon Workshop through any of the following means:

  • By installing either the Weapon Workshop bay or Weapon & Vehicle Workshop bay in your Mobile Operations Center.

  • By purchasing the Weapon Workshop for your Avenger.

  • By purchasing the Weapon Workshop for your Terrorbyte.

  • By setting up The Diamond Casino Heist and selecting the crew members. A Weapon Workshop will be available in your Arcade’s basement, across the Heist planning boards. It will be there until you complete or cancel the Heist.

Note that once you own a Weapon Workshop, you can also purchase certain weapons before reaching the Ranks required to unlock them. In other words, as long as you have a Weapon Workshop, you can buy the Combat MG and Heavy Sniper even at Rank 1.

The Weapons

Marksman Rifle Mk II

  • Price for the upgrade: $149,000

Marksman Rifle Mk II in Weapon\nWheel

The Marksman Rifle Mk II improves damage per shot over the original version. This improvement should be favored by PvP players who rely on this weapon. The Heavy Barrel attachment also increases damage of long-range shots, making it an even better weapon for sniping.

Combat MG Mk II

  • Price for the upgrade: $119,000

Combat MG Mk II in Weapon Wheel

The Mk II upgrade of Combat MG does not increase damage per shot very much. However, like many other Mk II weapons, Combat MG Mk II has muzzle brake accessories that reduce its recoil. Since the Combat MG has relatively high recoil, the muzzle brakes make the Mk II variant more accurate and useful. In The Doomsday Scenario finale, my Combat MG Mk II with muzzle brake was very effective in killing Cliffford Mercenaries in the control center.

Heavy Sniper Mk II

  • Price for the upgrade: $165,375

Heavy Sniper Mk II in Weapon Wheel

The Heavy Sniper’s Mk II upgrade not only significantly augments the weapon’s performance but also enables unique attachments not seen on any other Mk II weapon in GTA Online. The damage per shot is increased, the extended clip has larger capacity of 8 rounds, and you can install a suppressor on it, which is not available for the original Heavy Sniper. More importantly, the Thermal Scope is the unique accessory for this weapon that is very useful for searching enemies. It is vital for The Bogdan Problem’s Avenger Setup Mission.

Some players also choose to use Explosive Rounds on this weapon, turning it into a fabulous weapon against aircraft and flying vehicles. Rockets fired from the Homing Launcher or RPG take time to reach target, but the mechanics of Explosive Rounds are in no way different from ordinary bullets, meaning that they hit your target instantly.

Note that the Thermal Scope and the Explosive Rounds require Bunker Research to unlock.

Downgrading Mk II Weapons

The Mk II weapon upgrades are revertible, so feel free to give them a try when you want to test their performance. You can downgrade them for free, and after the restoration, you can redo the Mk II upgrade with no additional charge. Any accessories you purchased for the Mk II variant are also retained.